Mounting of the stator blades of gaseous fluid turbines



Jan. 13, 1953 H. s. RAINBOW ETAL MOUNTING OF THE STATOR BLADES OF GASEOUS FLUID TURBINES Filed July 10, 1950 2 SHEETS-SHEET 2 ih'lventors H J. emvaa/v 00AM! .0 94M.

Patented Jan. 13, 1953 UNITED STATES PATENT OFFICE MOUNTING OF THE STATOR BLADES OF GASEOUS FLUID TURBINES Application July 10, 1950, Serial No. 172,822 In Great Britain August 27, 1949 6 Claims. 1

. This invention relates to the mounting of the stator blades of a gaseous fluid turbine, and particularly in the case when the stator blades are hollow and adapted to be internally cooled by air flowing therethrough-as described, for example, in the specification of co -pending application No. 172,821, in the name of Horace Sinclair Rainbow and Donald Paul, filed concurrently herewith.

According to the invention, each stator blade of a row is supported at its radially inner end for radial outward withdrawal, being located in other directions at that end, and fast with its outer end is a platform which is clamped sandwich-fashion between stationary inner and outer co-axial rings providing location for the platform in all directions. Thus, in order to remove a blade the stationary outer ring must be'removed, whereupon any blade of that row can be withdrawn radially outwardly and replaced by a new blade when that is desired.

In the accompanying drawings Figure l is a fragmentary section of a gas turbine showing one of the stator blades of the first row arranged according to the invention; and

Figure 2 is a perspective view of the mounting for the radially-outer end. thereof.

In one construction according to the invention, as applied to the first stator blade row of a gas turbine the blades of which are arranged as disclosed in the specification aforesaid, the radiallyinner end ll of each hollow blade l2 extends slidingly through a correspondingly-shaped hole in a ring I3 which is welded or otherwise secured to the outwardly-directed flanges l4, I5 of a co-axial inner ring it providing, with the outer ring, an inner annular chamber 11 to receive cooling air which has passed radially inwardly of the blade, and direct it rearwardly, through holes It provided for the purpose on to the roots I9 of the first row of rotor blades 20. This inner ring 46 preferably has radially-inwardly directed teeth 2! for sliding engagement with teeth of a structural member 22.

The outer end 24 of the blade carries a platform 25 which is rhomboidal in plan view but part-cylindrical about the axis of the turbine and of such size as to form with the platforms of the rest of the blades (when assembled to provide the row) a continuous ring surface. This continuous ring surface is clamped, sandwich-fashion, between an inner ring 25 (having shaped holes to receive the outer ends of the blades) and an outer stator member 21 formed with outwardly di- 'rected channel flanges 28. 29 between which is more than one stage) The inner ring v26 is mounted in counter-bored grooves 35, 36 provided, at the forward edge of the ring 26, in .a flanged ring 31 which is bolted at 38 to the adjacent flange 28 of the stator member 21, and, at its rearward edge, in the first-stage rotor shroud 39 (assuming that the turbine has The rotor shroud 39 has an outward flange All which is bolted at 41 to the adjacent flange 29 of the stator member 21.

The exhaust cone assembly 43 is supported by an external channel-sectionring 44 forming the outer wall 45 of the outer annular chamber 30,, this external ring having an internal radial toothed engagement 45 with teeth '41 on the periphery of the flange 4'!) of the first stage rotor shroud It also has a flange 48 at its forward end which is bolted up, at 49, to the rearward end of the outer casing of the duct 32 with an interposed abutment ring 59. The latter has at least one axially-projecting 'tang 5|, within the interior of the outer annular chamber 38, which, when the parts are secured in position, nips the rearward flange 2B of the stator member 21 against the teeth 45 of the external ring 44 and against the flange 4'!) of' the first stage rotor shroud 39.

To dismantle the apparatus, the bolts 49 holding the external ring M. (which supports the exhaust cone assembly) are first removed and these parts then slid rearwardly, the toothed engagement 4%, 41 with the flange of the first stage rotor shroud 39 allowing of this. This discloses the mounting bolt. indicated at 53, for the second stage rotor shroud which, and the second stage stator 54, can then be removed. The abutment ring 53 can then be moved angularly in order to bring its tang 5| into alignment with a slot 55, provided for the purpose, in the flange 29 "of the stator member 27, whereupon the abutment ring can he slid axially rearwardly. This "provides access to the bolts 3-?! securing the forward flange 28 of the stator member to the flanged ring 37,

. thus enabling the stator member to be slidaxially 1 blades carrying platforms which. with the platforms of adjacent blades, form a continuous cylindrical ring adjacent said stator member, and an inner ring having holes slidably to receive and locate said blades, said cylindrical ring being disposed sandwich-fashion between said inner 3 ring and said stator member so that,'on axial removal of said stator member, any of said blades and its associated platform can be separately withdrawn in the radially outward direction.

2. A stator, of a gaseous fluid axial-flow turbine, comprising an annular stator member formed with outwardly-directed channel flanges between which is constituted an annular chamher, a row of hollow blades, means supporting the inner ends of said blades against movement in all directions but the radial one, the outer extremities of said blades extending through and carrying platform which, with the platforms of adjacent blades, form a continuous cylindrical inwardly-directed flange adjacent the other axial side, an internal annular stator member with outwardly-directed flanges, a shroud ring having an outwardly-directed flange, said shroud ring flange bolted up to one of the flanges of said stator member and having a toothed engagement with said inwardly-directed flange of said external ring allowing of relative axial movement thereof, said stator member jointly providing with said external ring an annular space, open ring adjacent said stator member, and an inner 3. A stator, of a gaseous fluid axial-flow turbine, comprising an annular stator member formed with outwardly-directed channel flanges, a row of blades, means supporting the inner ends of said blades against movement in all directions but the radial one, the outer extremities of said blade carrying platforms which, with the platforms of adjacent blades, form a continuous cylindrical ring adjacent said stator member, an inner ring having holes slidably to receive and locate said blades, said inner ring clamping the platform ring sandwich-fashion against said stator member so that, on removal of said stator member, any of said blades and its associated platform can be separately withdrawn in the radially outward direction, a flanged ring bolted to one of said channel flanges, and a shroud ring boltedto the other of said channel flanges, said flanged ring and said shroud ring both being counter-bored to receive and locate the edges of said inner ring.

4. A-stator, of a gaseous fluid axial-flow turbine, comprising an annular stator member formed with outwardly-directed channel flanges, a row of blades, means supporting the inner ends of said blades against movement in all directions but the radial one, the outer extremities of aid blades carrying platforms which, with the platforms of adjacent blades, form a continuous cylindrical ring adjacent said stator member, an inner ring having holes slidably to receive and locate said blades, said inner ring clamping the platform ring sandwich-fashion against said stator member so that, on removal of said stator member, any of said blades and its associated at the axial side remote from said shroud ring, to receive cooling air, an abutment rin bolted up to the outwardly extending flange of said external ring, said abutment ring having at least one tang extending across said annular chamber to hold the said one flange of said stator member against the flange of said shroud ring and against the internal flange of said external ring, the said one flange of said stator member having a slot in it to receive said tang when said abutment ring is turned angularly with respect to said stator member, a flanged ring bolted to the other flange of said stator member, a row of hollow blades, means supporting the inner ends of said blades against movement in all directions but the radial one, the outer extremities of said blades carrying platforms which, with the platforms of adjacent blades, form a continuous cylindrical ring adjacent said stator member, said stator member having holes in it to place said annular space in communication with the open outer ends of said blades, and an inner ring having holes slidably to receive and locate the outer ends of said blades, said inner ring I clamping said cylindrical ring sandwich-fashion against said stator member.

6. A stator, of a gaseous fluid axial-flow turbine, comprising an annular stator member, a row of blades, means supporting the inner ends of said blades against movement in all directions but the radial one, the outer extremities of said blades carrying platforms which, with the platforms of adjacent blades, form a continudus cylindrical ring adjacent said stator member, an

= inner ring having holes to slidably receive and locate said blades, said platform ring'being disposed sandwich-fashion between 'said stator member and said inner ring so that, on removal of said stator member, any of said blades and 1 it associated platform can be separately with- REFERENCES CITED The following references are of record inthe file of this patent:

UNITED STATES PATENTS Number Name Date 2,402,418 Kroon June 18, 1946 2,417,486 Hagemann et al. Mar. 18, 1947 2,427,244 Warner Sept. 9, 1947 OTHER REFERENCES Publication entitled Flight, vol. Lvn,

issue 2158, page 544, dated May 4, 1950. 

